Transmission circuits



Nbv. 11 192 4.

w J. W- HORTON m Nsmxs'idN CIRCUITS Filed Sept. 30, 1922 ml/enfor jg W. Hal 70 M Amy.

JOSEPH W. HORTON, OF BLOOMEIELD,

COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION: OF NEW YORK.

NEW JERSEY, ASSIGNOR TO WESTMN ELECTRIC 'rnensiarssiou craourrs.

Application filed September To all (whom it may concern:

Be -it known that I, J QSEPE W. HORTON, a citizen of, the United States, residing at Bloomfield, in the county of Essex, State of New Jersey, have invented certain new and useful Improvements in Transmission Circuits, of which the following is a; full, clear, concise, and exact descr1pt1on.

This invention relates to transmission circuits and has for one object the provision,

The arrangement consists, briefly in one ormore vacuum tube amplifiersor-other amplitying devices, connected across the hne, a c aracteristic of whichis to be tested.- The output of the amplifier by anon-inductive coupling is connected to the input terminals of a vacuum tube rectifier or a detector, the output circuit of, which includes: a'direct current measuring instrument. Bridged across the input terminals of the rectifier is the high impedance windingofa transformer, the low impedance winding of which is connected to an alternating current translating "device, such as a telephone receiver. The.

combined arrangement therefore may be employed for giving both audible and vis-, ible indications of the strength of the signal ing currents in the line to which the amphfier is connected. y The drawing illustrates a combined amplier-rectifier circuit embodying this inven ii-fl: Y

Referring in detail to the drawing, a transmission or signaling line 5, 5 is disclosed, and it will be assumed that it is'vdesired to obtain both visible and audible indications of the strength of the signaling currents therein,1'in order to determine if satis factory transmission is being maintained; The testing arrangement of this invention comprises a vacuum tube amplifier7, having its input terminals 8 and 9' connected across 30, 19 22. Serial No. 591,486.

line 5, 5 by a step-up transformer 10, which -preferably should have such a transforma tion ratio that substantially no transmission loss produced by this connection of the high impedance input circuit of tube 7 across the line. The output circuit of tube 7 includes between the anode 11 and cathode The primary winding 12 of this transformer is also included in the input circuit .of a vacuum tube detector or rectifier 16, in the output circuit of which is a direct current measurm instrument17, which may, for examp e, be a direct current milliammeter. -A

battery or other source of voltage 18 may be employed in series withthe primary wind ing 12 to maintain the control electrode 19 of detector 16 sufliciently negative to reduce ,the space current of the rectifier to zero, when no alternating current voltage is impressed on the detector from the amplifier 7-. This arrangement'makes it possible to I secure on the direct current meter 17, a deflection which is a function of the strength of the transmission currents in line 5, 5. If

transformer 13 is so designed that winding 12 is of very high impedance, the connection of the input electrodes of the detector across the primary winding of this transformer will make it possible to secure this meter deflection with a very small loss in the A. C. output of the transformer. v The secondary wmding 14 of transformer 13 should preferably be a low impedance winding so as to step down the impedance of the output circuit of tube 7 to the order of the impedance of the telephone receiver. I Space current for'the two tubes, 7 and 16, is supplied from a common source 'of voltage 20, which is connected to anode 11 througha series retardcoil 21, and which is connected to the anode of tube 16- through the meter 17. A heating current is supplied to the two filaments by a suitable'source of voltage'23. A condenser 24' may be employed to keep the direct current from source 20 out of the primary winding 12 of the transformer 13.

It is to be understood that the e-mbodiment of this invention described above is capable, of many and substantial modifications without departing in any wise from the spirit of this invention as defined in the appended claims.

The invention claimed is:

1. In combination, a plurality of electric discharge devices connected in tandem, each comprising an anode, a cathode and a control electrode, means for connecting the first ofvsaid devices to an alternating current line, one of said devices being adjusted to operate as a rectifier, a direct current instrument responsive to the current rectified thereby, a high impedance transformer Winding connected in shunt to the control electrode and cathode of said rectifier, and means for inductiyely connecting a telephone receiver to said winding.

2. Means for testing a signaling line comprising an amplifier having input and output terminals, said input terminals being so connected to saidline to present a practically infinite impedance when viewed from said line, a vacuum tube rectifier having input and output terminalsresponsive to the currents amplified'by said amplifier, a direct current measuring instrument connected to the output terminalsof said rectifier for giving a visible indication of the strength of the signalsin said line, a transformerhaving a high impedance winding connected across said rectifier input terminals, a low impedance winding for said transformer, and means connected to said low impedance winding for translating alternating current into energy of a different character.

3. Means for testing a signaling line comprising an amplifier havinginput and outu put terminals, atransformer for connecting said input terminals to said line, said transformer has a practically infinite impedance when viewed from said line, a vacuum tube detector comprisingan anode, a cathode and a -control electrode, a non-inductive connec- 1 tron-between the output terminals of said amplifier and the control electrode and cath- ;-ode of said detector, means for giving a visible indication of the strength of the signals detected by said detector, a high llllpedance transformer winding connected betweensaidjcontrol electrode and said cathode, and. means associated with the sec ond winding of. said transformer for giving an audible{-'indic'ation of the strength of the signals' ii;ii said linen 4. 'Means for testing a signaling line comprising a vacuum tube amplifier having an anode, a cathode and a control electrode, a rectifier comprising an'anode, a cathode and a control electrode, a step-up transformer for connecting the control electrode and cathode of said amplifier across said line, a

connection including a condenser between the anode of said amplifier and the control electrode of said rectifier, a connection-between. said cathodes, a shunt path across said connections at a point on said first connection between said condenser and thecontrol electrode of said rectifier, said shunt path comprising a high impedance trans said rectifier, a high impedance transformer Winding 1n shunt to said connections, a telephone receiver, means for coupling said receiver to said windlng and .a current measuring instrument responsive to the current rectified by said rectifier.

6. Means for testing a signaling line comprising an, amplifier having input and output terminals, said input terminals being so connected to said line as to present a prac tically infinite impedance when viewed from said line, line, a transformer having a high impedance primary winding connected to said output terminals and having a low impedance secondary winding connected to said outgoing line, a vacuum tube rectifier having electrodes connect-ed across said primary winding and a direct current measuring instrument responsive to the current rectified by said rectifier.

In witness whereof, I hereunto'subscribe my name this 27th day of September, A. D., 1922.

JOSEPH W. HORTON.

an outgoing alternatingcurrent 

